The combined company will have total sales of about $18 billion annually and more than 36,000 employees. About a quarter of its sales will now come from private labels.

ConAgra chief executive Gary Rodkin said the Omaha, NE-based company remains committed to its brands, which include Chef Boyardee pastas and Slim Jim meat snacks, but it anticipates that growth in private-label food, driven by the recession, will continue to outpace branded food growth.

Ralcorp's products include pasta, cereals, snacks, sauces and frozen bakery goods. Based in St. Louis, MO, the company makes private-label foods for Wal-Mart Stores Inc., Kroger Co. and McDonald's Corp., among other retailers.

The deal includes the assumption of Ralcorp's debt, bringing the total value of the transaction to about $6.8 billion. It is expected to close by March.

Last year, Ralcorp rejected several bids by ConAgra, including an offer for $5.17 billion, or $94 a share. Ralcorp opted instead to spin off its Post cereal business and focus on its private-label foods business. The latest ConAgra deal, valued at $90 a share, is close to what it offered before Ralcorp's split with Post.

The Ralcorp purchase is the largest in a recent spree of acquisitions of private-label manufacturers by ConAgra, including pretzel manufacturer National Pretzel and pita chipmaker Kangaroo Brands. The packaged food giant has also been focused on bolstering its portfolio of branded products, most recently with its purchase of Unilever's Bertolli and P.F. Chang's frozen meals businesses.